1. Field of the Invention
The present invention relates to an apparatus for bending glass panes in a horizontal position, comprising a bending mold disposed above the conveying plane for the glass panes and an endless conveyor belt, consisting of a heat-resistant flexible material and guided over deflector rolls, which conveys the glass pane heated to a bending temperature from the furnace to the bending mold and from the bending mold to the cooling or toughening station.
2. Description of the Related Art
An apparatus of this type is known from DE-AS 14 71 872. In this apparatus, a height-adjustable frame bending mold is disposed beneath the upper side of the endless conveyor belt, which bending mold, by raising, presses the conveyor belt together with the glass pane resting thereon against the stationary, upper bending mold. The lower frame bending mold then again descends and the bent glass pane is conveyed onwards on the flat conveyor belt. In order that the pane shall not deform, air nozzles are associated with the upper bending mold which, during the lowering movement of the lower mold, cool the glass pane in order to increase its shape stability. This method is, however, at most possible for relatively thick glass panes having a thickness of more than 6 mm; in the case of thinner glass panes, so much heat is removed by the cooling from the glass pane that subsequent toughening is no longer possible.
An apparatus of the initially named type is also known, wherein a height-adjustable bending mold is disposed also beneath the upper side of the endless conveyor belt, but which, together with the upper bending mold, moves synchronously with the conveyor belt during the pressing operation (U.S. Pat. No. 4,318,728). In this case the conveyor belt is held flat, and the glass pane lies, after bending, only along linear zones on the flat conveyor belt, so that in this case a considerable risk of deformation of the bent glass pane due to the action of its self-weight exists.